Li Fang, He Jian, Liu Jiandong, Wu Mingguang, Hou Yuyang, Wang Huaping, Qi Shihan, Liu Quanhui, Hu Jiawen, Ma Jianmin
School of Physics and Electronics, Hunan University, Changsha, 410082, China.
CSIRO Mineral Resources, Clayton, VIC, 3168, Australia.
Angew Chem Int Ed Engl. 2021 Mar 15;60(12):6600-6608. doi: 10.1002/anie.202013993. Epub 2021 Feb 8.
The structures and components of solid electrolyte interphase (SEI) are extremely important to influence the performance of full cells, which is determined by the formulation of electrolyte used. However, it is still challenging to control the formation of high-quality SEI from structures to components. Herein, we designed bisfluoroacetamide (BFA) as the electrolyte additive for the construction of a gradient solid electrolyte interphase (SEI) structure that consists of a lithophilic surface with C-F bonds to uniformly capture Li ions and a LiF-rich bottom layer to guide the rapid transportation of Li ions, endowing the homogeneous deposition of Li ions. Moreover, the BFA molecule changes the Li solvation structure by reducing free solvents in electrolyte to improve the antioxidant properties of electrolyte and prevent the extensive degradation of electrolyte on the cathode surface, which can make a superior cathode electrolyte interphase (CEI) with high-content LiF.
固体电解质界面（SEI）的结构和组成对于影响全电池性能极为重要，而这又由所使用的电解质配方决定。然而，从结构到组成来控制高质量SEI的形成仍然具有挑战性。在此，我们设计了双氟乙酰胺（BFA）作为电解质添加剂，以构建梯度固体电解质界面（SEI）结构，该结构由具有C-F键的亲锂表面均匀捕获锂离子和富含LiF的底层引导锂离子快速传输组成，从而实现锂离子的均匀沉积。此外，BFA分子通过减少电解质中的游离溶剂来改变锂溶剂化结构，以提高电解质的抗氧化性能，并防止电解质在阴极表面大量降解，从而形成具有高含量LiF的优质阴极电解质界面（CEI）。
